Small cells implementing multiple air interfaces

ABSTRACT

A communication networks including a plurality of small cell providing air interface infrastructure functionality is provided. Aspects of the present disclosure relate to the management of inter-small cell communication in accordance multiple air interfaces supported within individual small cells. Additionally, aspects of the present disclosure relate to the management of intra-small cell communication in accordance with communication networks implementing multiple small cells. In other aspects, small cells coordinate handovers through the use of a controller, or by leveraging wireless connections created between the small cells. In further aspects, the small cells enable the utilization of multiple air interface standards within a small cell.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 61/531,311 entitled UNIFIED MULTITECHNOLOGY SYSTEMS ANDMETHODS and filed on Sep. 6, 2011. U.S. Provisional Patent ApplicationNo. 61/531,311 is incorporated by reference herein.

BACKGROUND

Wireless networks are networks that use radio waves to carry informationfrom one node in the network to one or more other nodes in the network.Wired communication can also be used in portions of a wireless network,such as between cells or access points. Wireless networks are used inconnection with many applications, including, for example, satellitecommunications systems, portable digital assistants (PDAs), laptopcomputers, and mobile devices (including cellular telephones and userequipment). Users of such applications can connect to a network as longas the user is within range of such a wireless communication technology.The range of the wireless communication technology can vary depending onthe deployment.

Cellular wireless networks are characterized by the use of base stationsthat provide radio coverage for a geographic area, with multiple basestations arranged to provide contiguous radio coverage over a largerarea. Generally, when a mobile station is positioned within a coveragearea of a base station, the mobile station can communicate in accordancewith an air interface communication protocol with the base station. Inturn, the base station can provide voice and data access to the mobilestation via one or more circuit-switched, packet-switched signaling ortransport networks.

The geographic coverage area of a base station is sometimes defined interms of a geometric shape of a cell and base stations can often bereferred to as “cells.” Generally, the coverage area associated with agiven cell may be logically divided geographically into a number ofsectors, with each sector being defined respectively by radiationpatterns from directional antenna components or antennas of therespective base station. Base stations are typically not associated withany subscriber or small group of subscribers in particular. Rather, aservice provider will attempt to location base stations inpublicly-accessible locations for use by the service provider'scustomers generally.

Traditional base stations include macro cell transceivers that aretypically configured to provide wireless communications for users havingproperly configured mobile devices over several kilometers. The wirelesscommunications correspond to one or more wireless communication airinterface standards, such as second, third or fourth generation airinterface standards. To address gaps in a macro network coverage and forother reasons such as for relief from capacity constraints, macronetwork service providers have recently shown interest in lighterinfrastructure referred to as small cells, which may also be referred toas pico cells, small base stations, small BTSs, and by other names.Typical small cell base stations can include transceivers that providewireless communications for the properly configured mobile deviceswithin several hundreds of meters of a particular small cell.Illustratively, the small cells are configured to operate in accordancewith the same wireless communication air interface standards. Thecombination of macro and small cells by a service provider can beconsidered a heterogeneous network, in which the service provider mayattempt traffic offloading from macro base stations to small cell basestations.

In addition to supporting mobile air interface standards utilized by themacro cell transceivers, such as second, third and fourth generation airinterface standards and beyond, small cells can support additional radiocommunication protocols. Such additional radio communication protocols,such the IEEE 802.11 communication protocol, often referred to as(“Wi-Fi”). Wi-Fi standards may be unlicensed or implemented differentlyfrom the more traditional mobile air interface standards.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram of an embodiment of a small cell;

FIG. 2 is a block diagram of an embodiment of a heterogeneous networkincluding a plurality of small cells and macro cells;

FIGS. 3A and 3B are block diagrams of the heterogeneous network of FIG.2 illustrating embodiments of a handover between a macro cell and asmall and intra-small cell handovers;

FIGS. 4A and 4B illustrate the methodology of the handover mechanismwithin a single small cell;

FIG. 5 illustrates the handover process within a small cell from LTE toWi-Fi air interface standards;

FIG. 6 illustrates the handover process within a small cell from Wi-Fito LTE air interface standards;

FIGS. 7A and 7B illustrate embodiments of a control mechanism forhandovers between small cells;

FIG. 7C is a flow diagram illustrative of a small cell managementroutine implemented by a component of a heterogeneous network;

FIG. 8 illustrates another embodiment of a handover between small cells;

FIGS. 9A-9C illustrate an embodiment of translation of quality ofservice standards within a heterogeneous network; and

FIG. 10 illustrates an embodiment of a location service implemented withsmall in a heterogeneous network.

DETAILED DESCRIPTION

Generally described, the present disclosure relates to communicationnetworks including a plurality of small cell providing air interfaceinfrastructure functionality. Specifically, aspects of the presentdisclosure relate to the management of inter-small cell communication inaccordance multiple air interfaces supported within individual smallcells. Additionally, aspects of the present disclosure relate to themanagement of intra-small cell communication in accordance withcommunication networks implementing multiple small cells. In anillustrative embodiment, handovers between multiple radio technologieswithin a single small cell may utilize home-foreign agent technologyused in the Mobile IP (MIP) standard. In other aspects, small cellscoordinate handovers through the use of a controller, or by leveragingwireless connections created between the small cells. In furtheraspects, the small cells enable the utilization of multiple airinterface standards within a small cell. For example, to supportintra-small cell handover, a single small can support the translation ofquality of service (“QoS”) standards for continuous communications withnetwork infrastructure equipment.

Although one or more aspects of the present disclosure will be describedwith regard to illustrative embodiment or examples, one skilled in therelevant art will appreciate that each aspect of the present disclosurecan be implemented separately or that various combination of aspects maybe combined. Accordingly, no particular combination of aspects of thepresent disclosure should be inferred.

A heterogeneous network which supports multiple communicationtechnologies (e.g., communication in accordance with multiple airinterface standards) in a unified architecture can provide near-termsolutions to capacity problems. Specifically, in one embodiment, aheterogeneous network can be configured such that the heterogeneousnetwork includes both macro-base cells and small cells and that supportlonger range wireless air interfaces (e.g., second, third, or fourthgeneration wireless air interface standards). Additionally, the smallcells can also support shorter range wireless air interfaces (e.g.,Wi-Fi) and further include functionality that facilitates handoverbetween other cells (macro cells and other small cells) and handoversfrom communications in accordance with the longer range wireless airinterface standards to communications in accordance with the shorterrange wireless air interface standards, and vice versa. Such aheterogeneous network can include the coordination of security, qualityof service, assessment of mobility of user equipment, authentication,provisioning systems, and the like.

FIG. 1 is a block diagram of illustrative components of an embodiment ofa small cell 100. As previously described, in one embodiment, the smallcell 100 may be configured to support communications in accordance withmultiple air interface standards. FIG. 1 illustrates an embodiment wheretwo illustrative air interface standards, a longer range wireless airinterface standard (e.g., the Long Term Evolution (“LTE”) fourthgeneration air interface standard and a shorter ranger wireless airinterface standard (e.g., the Wi-Fi air interface standard) aresupported with the same device. Additionally, the small cell 100 isconfigured to handover communications between the different airinterface standards within the small cell, and also between small cells.

Illustratively, the small cell 100 includes an integration of a set ofcomponents that facilitate transmission of data in accordance with thesupported wireless air interface standards, including, but not limitedto, antennas, filters, radios, base station control components, networkinterface components and power supplies. One skilled in the relevant artwill appreciate that all such components that could be implemented in asmall cell 100 are not illustrated for purposes of brevity and notlimitation. As illustrated in FIG. 1, the small cell 100 includes afirst and second component for receiving signals transmitted inaccordance with the supported air interface standards. In oneembodiment, the first radio component can corresponds to an LTE radio110 and the second radio component can corresponds to a Wi-Fi radio 120.The two radio components can be configured into a form factor thatfacilitates incorporation into the form factor desired for the smallcell 100. In other embodiments, the radios may be configured to supportother technologies, or more or less radios may be present in the smallcell. As also illustrated in FIG. 1, the small cell 100 can also includean additional radio component 130 for receiving signals in accordancewith an interface standard. The additional radio component 130 can beconfigured to receive signals in a manner redundant to either the firstor second radio components 110, 120 or in a manner additional to thefirst and second radio components

In various embodiments, the LTE radio component 110 may supportfrequencies from 700 MHz to 2600 MHz in frequency division duplex (FDD)and/or time division duplex (TDD) modes. In FDD embodiments, the LTEradio component 110 may provide a single RF carrier with support of upto 20 MHz FDD channels. Illustratively, the LTE air interface standardcan be considered a longer range air interface standard based on thelikely geographic range of communications between devices communicatingin accordance with the LTE air interface standard. In some embodiments,the Wi-Fi radio component 120 may support several frequency bandssimultaneously using multiple radios. For example, the Wi-Fi radiocomponent 120 may support communications in the 2.4 GHz and 5 GHzfrequency range. Illustratively, the Wi-Fi radio 120 may be configuredto have up to 40 MHz channels. Illustratively, the Wi-Fi air interfacestandard can be considered a shorter range air interface standard basedon the likely geographic range of communications between devicescommunicating in accordance with the Wi-Fi air interface standard.However, the characterization of air interfaces as longer range orshorter range does not necessarily imply the definition of any specificgeographic ranges. Rather, any interface standard may be considered alonger range or shorter range air interface standard relative to anotherair interface standard.

As illustrated in FIG. 1, the LTE radio component 110 and the Wi-Firadio component 120 are connected to a base station controller 140. Thecommunication controller 140 includes common control software andprovides operation and maintenance support for all technologiessupported by the small cell 100. The communication controller 140 caninclude the same or variations similar controllers included in otherinfrastructure equipment, such as macro cells. The communicationcontroller 140 is also connected to a backhaul interface 150 in thesmall cell 100. In various embodiments, the small cell 100 leverages aSmall Form factor Pluggable (SFP) module as the backhaul interface 150.This allows flexibility to backhaul traffic with fiber, PicoEthernet ora large variety of wireless backhaul products. As indicated in FIG. 1,the small cell 100 interfaces with various user equipment (UE) 160through antennas 170, and also with a core network 180.

The UEs 160 may correspond to any computing device having one or moretelecommunication components capable of communicating with the smallcell 100 in accordance with wireless air interface standards. The UE 160can illustratively include mobile phones, personal data assistants(PDAs), smart phones, tablet PCs, personal computing devices,appliances, and the like. Additionally, the telecommunication componentscapable of communicating with the small cell 100 can integrated directlyinto the UE or provided as an add-on component or supplementalcomponent. Still further, the telecommunications components capable ofcommunicating with the small cell 100 may be shared by two or more UEs.For example, two or more UEs may share communication componentsutilizing wired connections, often referred to as tethering, or via awireless communication protocol, often referred to as a hotspot.

In the architecture, the radio components 110, 120 in the small cell 100communicate with the carrier's core network 180 using industry standardcommunication protocols. For example, the LTE radio component 110 cantransmit information in accordance with the transfer control protocol(“TCP”) and Internet Protocol (“IP”) protocols.

FIG. 2 is a block diagram of an embodiment of a heterogeneous network200 including a plurality of small cells 100 (FIG. 1). As seen in FIG.2, heterogeneous network 200 can include small cells 100 in combinationwith network of macro cells 210. In accordance with traditional wirelessinfrastructure configurations, the small cells 100 and the macro cells210 would be in communication with one or more Mobility ManagementEntity (MME) 220 through one or more serving gateways 230. Thecommunication interface between the small cells 100 and the servinggateway 230 may be over a network interface, such as a S1 interface.Alternatively, the communication between the small cells 100 and theserving gateway 230 can be achieved via a public network, such as via S1interface utilizing a tunneling protocol. In various embodiments, acommon network management system (NMS) 240 (also referred to as networkmanagement device (NMD)) may be configured to oversee and unify therespective element management systems (EMS) for the macro network (EMS250) and the small network (EMS 260).

In general, in a heterogeneous network 200 supporting multiple airinterface protocols and technologies and including macro cells 210 andsmall cells 100, a UE 160 may communicate with a number of macro cells210 or small cells 100. In some instances, a UE 160 may sequentiallycommunicate between two macro cells 210. In other instances, a UE 160may sequentially communicate between a macro cell 210 and a small cell100, or vice versa. In still further instances, a UE 160 maysequentially communicate between two small cells 100. Generally, ahandover between, or an offload from, a first cell (e.g., a micro cell210 or small cell 100) and a second cell in which communications betweenthe UE and service provider correspond to the same air interfacestandard may be referred to as a horizontal handover or offload. In asimilar manner, a handover between a first cell (e.g., a macro cell 210or a small cell 100) in which communications between the UE 160 theservice provider utilizes multiple air interface standards can bereferred to as a vertical handover or offload.

Illustratively, handovers/offloads between two or more different airinterface standards within a single small cell 100 may be referred to asintra-small handovers/offloads. For example, a single small cell 100 mayelicit handover of a UE 160 communicating in accordance with the LTE airinterface standard to communicate in accordance with the Wi-Fi airinterface standard. Handovers/offloads between two or more small cells100 with the same heterogeneous network 200 may be referred to as intersmall handovers/offloads. As will be explained in greater detail below,in one aspect a small cell 100 can facilitate intra-small cell verticalhandover (LTE to/from Wi-Fi). In another aspect, a small cell 100 canfacilitate inter-small cell horizontal/vertical handover (LTE to LTE andLTE to/from Wi-Fi) between other small cells 100 or a macro cell 210.

These offloading capabilities of the small cell 100 help to increase thepossible traffic density or the number of ‘megabit per second per squaremile’ supported by a wireless network. In some embodiments, the trafficfrom the macro network can be offloaded leveraging Rel. 8 seamless LTEhandover between the macro and the small cell. Traffic allocation andload balancing decisions consider: user mobility/speed, type of session,current load, user density, location, and business model.

FIGS. 3A and 3B are block diagrams of the heterogeneous network 200 ofFIG. 2 illustrating one embodiment of the interaction of components inaccordance with a handover. Specifically, FIGS. 3A and 3B illustrate anindirect handover from a macro cell 210, managing communications with aUE 160 utilizing the LTE air interface standard to a small cell 100. Thecommunications between the UE 160 and the small cell 100 will correspondto the Wi-Fi air interface standards.

As indicated by the dotted lines of FIG. 3A, at (1), it is assumed thatthe UE 160 has established LTE-based communications with a macro cell210. At some point, the service provider network 180 determines that theUE 160 should be handed over between the macro cell 210 and a small cell100 at (2). The handover determination is the processed by the macrocell 210 and the small cell 100 at (3). As illustrated in FIG. 3A, thecommunications from the UE 160 are first offloaded from the macro cell100 to the small cell 100. The handover between the macro cell 100 andthe small cell 100 is facilitated such that the small cell communicateswith the UE 160 utilizing the same air interface standards, e.g., theLTE air interface standards. The UE 160 then establishes LTE-basedcommunications with the small cell 100 at (4).

With reference to FIG. 3B, at (5), from the receiving small cell 100conducts an intra-small handover with the UE 160 from the LTE radiocomponent 110 (not shown in FIGS. 3A and 3B) to the small cell Wi-Firadio component 120 (not shown in FIGS. 3A and 3B). The LTE to Wi-Fihandover is processed by the UE 160 at (6). Thereafter, communicationsbetween the UE 160 and the small cell 100 are facilitated in accordancewith the Wi-Fi air interface standard at (7). The handover processbetween a macro cell 210 and a small cell 100 can be repeated.Additionally, a similar handover process between two small cells 100 canalso be implemented in a similar manner. By way of an illustrativeexample, a passenger in a fast moving train may start a data session ontheir UE 160 connecting through any number of LTE macro cells 210 in aheterogeneous network 200. When the passenger arrives at a destination,communications with the UE 160 may be horizontally handed over to alocal small cell 100 utilizing the LTE air interface standards. Thepassenger may then be vertically handed off within the same small cell100 to the small cell Wi-Fi network, in an intra-small handover. In thisscenario, the data session was indirectly handed-off between the macrocell 100 LTE radio component to the small cell 100 Wi-Fi radiocomponent.

In a different scenario, different handovers may be accommodated by thesmall cell 100. For example, a person in a coffee shop in a mall maystart downloading a large data file on their UE 160 over communicationswith a small cell 100 in accordance with the Wi-Fi air interfacestandards. At some point during the communications between the UE 160and the small cell 100, the UE 160 (e.g., the user) may begin movementapproaching the limits of the range for the small cell's Wi-Fi radiocomponent 120. In this scenario, the data session may be handed overfrom the Wi-Fi radio component 120 on a small cell 100 to the LTE radiocomponent 110 on the same small cell 100. Still further, if the personcontinues moving in a manner that approaches the limits of the smallcell's LTE radio component 110, then there would be an inter small cellhandover, horizontally (LTE radio component to LTE radio component)between two small cells. Still further, the second small cell (e.g., thereceiving small cell 100) could then possibly instigate a furthervertical intra small cell handover to the small cell's Wi-Fi radiocomponent 120. In this example the data session will experience servicecontinuity through intra and inter small cell handoversWi-Fi-LTE-LTE-Wi-Fi. The control mechanism and the interfaces involvedin the inter-small cell handover are described further below withreference to FIGS. 5 and 6.

As described above, a single small cell 100 allows for handoversutilizing communications in accordance with multiple air interfacestandards (e.g., vertical handovers). Specifically, in an illustrativeembodiment, a small cell 100 may vertically handover a UE 160 between anLTE radio component 110 and a Wi-Fi radio component 120. FIGS. 4A and 4Billustrate a methodology of the vertical handover mechanism within asingle small cell 100. In one embodiment, the small cell 100 can utilizehome-foreign agent technology used in the Mobile IP (MIP) protocol tofacilitate that inter-small handover.

Generally, the Mobile IP protocol allows location-independent routing ofIP datagrams on the Internet. Each mobile node is assigned or otherwiseidentified by a home network address (e.g., an IP address), which istypically associated with a home network, such as a mobile serviceprovider. In embodiments in which a mobile node establishescommunication within its home network, the mobile node communicates withthe home agent of the home network. Communications from the mobile nodeare passed from the mobile node, through the home agent, and on to thecore network. In embodiments in which the mobile node establishescommunication with a network that is not a home network (e.g., a guestnetwork), a mobile node is associated with a temporary network address(e.g., a care-of address) which identifies its current location on theguest network. Additionally, the mobile node's home address isassociated with the local endpoint of a tunnel to a home agent providedby the home network. In one aspect, the Mobile IP protocol specifies howa mobile node registers with its home agent and how the home agentroutes datagrams to the mobile node through the tunnel.

A node wanting to communicate with the mobile node uses the permanenthome address of the mobile node as the destination address that receivespackets. Because the home address logically belongs to the networkassociated with the home agent (e.g. the home network), normal IProuting protocols/components initially forward these packets from asender to the home agent of the home network. Instead of forwardingpackets to a destination that is physically in the same network as thehome agent, the home agent redirects these packets towards the remoteaddress through an IP tunnel by encapsulating the datagram with a new IPheader using the care of address of the mobile node.

When acting as transmitter, a mobile node sends packets directly to theother communicating node, without sending the packets through the homeagent, using its permanent home address as the source address for the IPpackets.

With reference to FIG. 4A, in one embodiment, to facilitate inter-smallhandovers, a small cell 100 includes a home agent (HA) 402 for the LTEair interface standard and a HA 404 for the Wi-Fi air interfacestandard. In this embodiment, each home agent, HA 402 and HA 404, isassociated with the same core network 180 and hosted on the same smallcell 100. Illustratively, a specific home agent is utilized tofacilitate communications between a UE 160 and the core network 180based, at least in part, on which air interface standard is utilized toinitiate communications between the UE 160 and the small cell 100. Forexample, the LTE home agent, HA 402, would be utilized to establishcommunications between the UE 160 and the core network 180 if the UE 160established communications with the small cell 100 in accordance withthe LTE air interface standard. Similarly, the Wi-Fi home agent, HA 404,would be utilized to establish communications between the UE 160 and thecore network 180 if the UE 160 established communications with the smallcell 100 in accordance with the Wi-Fi air interface standard. As will beexplained in detail below, each home agent node may be associated with adifferent network address by the core network 180.

Additionally, the small cell 100 includes a foreign agent node (FA) 406for the LTE air interface standard and a foreign agent node FA 408 forthe Wi-Fi air interface standard. The foreign agent nodes function asthe interface between the UE 160 and the small cell 100. Thedetermination of which foreign agent node is a current foreign agentnode will be dependent on the air interface standard utilized forcommunications between a UE 160 and the small cell 100.

In one aspect, each home agent node, HA 402 or HA 404, utilizes MIPtunnels, or other communication tunnels, to communicate with arespective foreign agent node, FA 404 or FA 406 (e.g., a matchingforeign agent node). For example, an initial LTE-based communicationbetween a UE 160 and a small cell 100 would utilize an MIP tunnel 410between the LTE HA 402 and the LTE FA 406. Similarly, an initialWi-Fi-based communication between the UE 160 and a small cell 100 wouldutilize an MIP tunnel 410 between the Wi-Fi HA 404 and the Wi-Fi FA 408.Each HA 402 or HA 404 may be addressable by different network addressesassigned or accepted by the core network 180.

In another aspect, each home agent, HA 402 or HA 404, utilizes MIPtunnels, or other communication tunnels, to communicate with an oppositeforeign agent node, FA 408 or FA 406, respectively (e.g., an oppositeforeign agent node). Illustratively, a home agent node will not changeonce communications between a UE 160 and the core network 180 areinitiated. To facilitate an air interface handover, the home agent nodewill utilize communication tunnels to a different foreign agent node.For example, for a communication initiated in accordance with the LTEair interface standard but that has been handover to the Wi-Fi airinterface standard would utilize an MIP tunnel 410 between the LTE HA402 and the Wi-Fi foreign agent 408. Similarly, for a communicationinitiated in accordance with the Wi-Fi air interface standard but thathas been handover to the LTE air interface standard would utilize an MIPtunnel 410 between the Wi-Fi HA 404 and the LTE foreign agent 406. Insome embodiments, however, the UE 160 would remain addressable by thenetwork address associated with the original home agent node. Using theMIP tunnel 410 between the home and foreign agents allows the small cell100 to make the handovers between LTE and Wi-Fi air interface standardswithout breaking a communication channel. Data communications can beoffloaded from the LTE to Wi-Fi air interface standards (or vice versa)by switching between the respective MIP tunnels 410. The various passthrough and switch combinations between the HAs 402, 404 for LTE andWi-Fi and the Fas 406, 408 for LTE and Wi-Fi provide what is referred toas 2×2 support. Accordingly, the handover between the air interfacestandards within a small cell 100 s may be considered to be independentof communications with the core network 180. In some embodiments, thecore network 180 may not have any knowledge of a current air interfacestandard being utilized between a UE 160 and a small cell 100 or when anintra small cell handover has occurred.

To illustrate the HA-FA architecture in more detail, an example intrasmall LTE-to-Wi-Fi handover will now be described with reference to FIG.4B. For illustrative purposes, assume that a UE 160 has initialized anLTE-based communication channel with the small cell 100. As previouslyindicated, the LTE data may flow from the UE 160 to the core networkwould be associated with a network address associated with the HA 402,e.g., IP 10.116.150.5. Accordingly, data received at the LTE HA 402would be passed through to the LTE FA 406 via the MIP tunnel 410, andmade available to a UE 160 on IP 10.116.150.5, as received.

At some point, assume for an illustrative example, that the small cell100 determines that handover to the Wi-Fi air interface standard shouldoccur between the UE 160 and the small cell 100. In this example, theLTE HA 402 would use a MIP Tunnel 410 to switch the data flow over tothe Wi-Fi FA 408 (which has a proxy MIP inside). As illustrated in FIG.4B, the small cell provides data on a Wi-Fi interface of a UE 160 withIP 10.116.200.6 corresponding to the foreign agent node FA 408. However,because of the utilization of the MIP tunnel 410, the UE 160 continuesto receive data flow associated with the original IP address of the LTEhome agent HA 402. Further details of the handover process within asmall cell 100 in the two directions (LTE-Wi-Fi and Wi-Fi-LTE) areprovided below, with reference to FIGS. 5 and 6. Additionally, the homeagent node, HA 402, can continue to utilize the MIP tunnels 410 toeffectuate multiple handovers.

FIG. 5 illustrates the handover process within a small cell from LTE toWi-Fi air interface standards. As illustrated in FIG. 5, initial trafficmay be on the LTE interface between the UE 160 and the LTE Access Point(AP)/FA 406. Since there is a MIP Tunnel 410 formed between the HA 402and the LTE Access Point (AP)/FA 406, there is data flow in accordancewith the LTE air interface standards from the LTE HA 402 to the LTEAccess Point (AP) 406, and to the UE 160. If the UE 160 triggers ahandover, the handover process is initiated. A handover may be triggeredfor a variety of reasons. For example, there may be a problem with theLTE signal, there may be a new Wi-Fi network discovered, the user mayhave just subscribed to a Wi-Fi network, the user may become lessmobile, there may be too many users on the access point, and the like.

With continued reference to FIG. 5, once the handover is triggered,there is a Dynamic Host Configuration Protocol (DHCP) request sent fromthe UE 160 to the Wi-Fi FA 408. The Wi-Fi FA 408 then contacts the DHCPserver 502, which may be within the small cell or somewhere on the corenetwork, to obtain a DHCP address. The DHCP server 502 acknowledges theWi-Fi FA 408 request. Then the Wi-Fi FA 408 sends a MIP Register Requestto the LTE HA 402, and the LTE HA 402 responds to the Wi-Fi FA 408, andcreates a MIP Tunnel 410 between the LTE HA 402 and the Wi-Fi FA 408.Then the Wi-Fi FA 408 acknowledges the UE's DHCP request, and there isdata flow created between the LTE HA 402 and the UE 160 via the Wi-Fi FA408.

FIG. 6 illustrates the handover process within a small cell 100 fromWi-Fi to LTE air interface standards. As illustrated in FIG. 6, initialtraffic may be on the Wi-Fi interface between the UE 160 and the Wi-FiAccess Point (AP)/FA 408. Since there is a MIP Tunnel 410 formed betweenthe HA 404 and Wi-Fi AP/FA 408 for Wi-Fi, there is data flow inaccordance with the Wi-Fi air interface standard from the Wi-Fi HA 404to the Wi-Fi FA 408, and to the UE 160. If the UE 160 triggers ahandover, the handover process is initiated.

With continued reference to FIG. 6, once the handover is triggered,there is a DHCP request sent from the UE 160 to the LTE FA 406. The LTEFA 406 then contacts the DHCP server 502 within the small cell 100 toobtain a DHCP address. The DHCP acknowledges the LTE FA 406 request.Then the LTE FA 406 sends a MIP Register Request to the Wi-Fi HA 404,and the Wi-Fi HA 404 responds to the LTE FA 406, and creates a MIPTunnel 410 between the Wi-Fi HA 404 and the LTE FA 406. Then the LTE FA406 acknowledges the UE's DHCP request, and there is data flow createdbetween the Wi-Fi HA 404 and the UE 160 via the LTE FA 406.

FIG. 7A illustrates an embodiment for managing handovers between a setof small cells 100A-100X in inter-small cell handovers in aheterogeneous environment 200. In some embodiments, it is possible tohave the small cells 100 be autonomous and self-sustaining devices,where each small cell runs the necessary management functionsindependently. In such embodiments, the small cells may be referred toas “standalone” or “autonomous” small cells. In the embodiment of FIG.7A, the heterogeneous environment 200 can include Wi-Fi/LTE controller702 is used to run some of the high-level management functions performedon each of the small cells from one centralized point, thereby enablingthe small cells 100 to be “thin” devices. The high-level managementfunctions may include controlling the quality of service of data acrossthe different technologies, the triggering of handovers between airinterface standards within a small cell 100 (e.g., intra small cellhandovers), the triggering of handovers between cells based on variouscriteria (e.g., inter call handovers), the collection of statistics, themonitoring of signal levels, pre-planning of handovers in somelocations, security management, location tracking, and the like.

With reference again to an illustrative example above where a person ina mall is downloading a large data file on their UE 160 over Wi-Fi airinterface standard and then walks outside the coffee shop to anotherpart of the mall, the data session may be handed-off from the Wi-Firadio component 120 on a first small cell 100 to the LTE radio component110 on the same small cell 100 without using the controller 702. Whenthe person continues walking and arrives to a new small cell zone, thenthe inter-small cell handover, horizontally (LTE to LTE) would becoordinated by the controller 702. Then, the vertical hand-off to theWi-Fi hotspot in the new small cell can again be controlled by the smallcell itself, without the controller.

The controller 702 can also be used to offload traffic from carrier toan enterprise, for example. There may be a controller for a plurality ofsmall cells 100 in a carrier network, and another controller for anotherplurality of small cells in an enterprise network. When a UE 160 movesfrom the carrier network (for example from the street) into theenterprise network (for example into a building), the controllerscommunicate with one another to seamlessly handover the traffic from thecarrier to the enterprise network of small cells. Additionally, in someembodiment, the controller 702 can implement the various managementfunctions independent of instructions received from core networkcomponents or without the knowledge of core network components.Illustratively, the controller 702 may communicate with the core network180. Additionally, although not illustrated in FIG. 7A, each small cell100 may maintain a data communication with the core network 180 throughgateway 230. Alternatively, at least some portion of the small cells 100may communicate with the core network 180 through the controller 702.

With reference to FIG. 7B, in another embodiment, the heterogeneousnetwork 200 can include a set of controllers 702A and 702B forimplementing various management functions associated with a set of smallcells 100. For example, a set of controllers 702A and 702B may beassociated with multiple small cells 100 based on geographic criteria,such as associating a single controller 702A and 702B to identifiableregions or locations. In this example, each controller 702A and 702Bcould operate substantially independent of each other. In anotherexample, a set of controllers 702 A may be configured such that eachcontroller 702 is associated with a particular service provider. In thisexample, a particular region or geographic location may have multiplecontrollers 702A and 702B. As illustrated in FIG. 7B, controller 702Amay also interface with a macro cell 210, directly or indirectly, tofacilitate at least some portion of the management functions.Additionally, controllers 702A and 702B may communicate to distributemanagement functions, to coordinate specific handovers, or tosynchronize management information or other information. Although FIG.7B illustrates a limited number of controllers 702 and small cells 100,one skilled in the relevant art will appreciate that the number andconfiguration of the controllers and small cells is not limited toillustrations.

With reference now to FIG. 7C, in yet another embodiment, aheterogeneous environment 200 can include a set of controllers 702 thatmay be hierarchically arranged such that a portion of the managementfunction is distributed among the hierarchically arranged controllers.In this embodiment, the set of controllers may be associated withvarious small cells 100 or macro cells 210 in the manner described abovewith regard to FIG. 7B or with regard to other organizational criteria.As illustrated in FIG. 7C, one or more controllers 702T may be incommunication with other controllers 702A-702X. The one or morecontrollers 702 represent an additional layer of controllers that cancoordinate communications between controllers or implement some portionof the management functions for a set of controllers. For example, thecontroller 702T may function as a master controller for a region, aservice provider, enterprise network or the like. In another embodiment,the controller 702T may coordinate handovers between controllers thathave different capabilities or functions. As described above, althoughFIG. 7C illustrates a limited number of controllers 702 and small cells100, one skilled in the relevant art will appreciate that the number andconfiguration of the controllers and small cells is not limited toillustrations. Similarly, although only one additional level ofcontroller is illustrated in FIG. 7C, the heterogeneous network 200 canalso include any number of additional controller per level and anynumber of levels in a hierarchy.

FIG. 8 illustrates the coordination of handovers between “standalone” or“autonomous” small cells 100 within a heterogeneous environment 200. Inthe embodiment illustrated in FIG. 8, a controller, or other controlmechanism, is not necessarily used to coordinate handovers between smallcells 100. Rather, the small cells 100 communicate with one another tocoordinate and execute handovers between them. In some embodiments, itis possible to use the X2 interface, which is an interface allowing theinterconnection of small cells 100 or macro cells 210 (not shown in FIG.8) to each other.

Generally described, some communication interfaces, such as the X2interface, are generally designed to support signaling informationbetween cells over a wired connection. For example, one or more macrocells 210 (not shown in FIG. 8) can utilize an interface such as the X2interface to coordinate handovers as facilitated through communicationstransmitted via the core network 180. In accordance with an embodimentof the present disclosure, however, the small cells 100 may facilitatethe transmission of control information for coordination of handovers.Illustratively, the small cells 100 can utilize the Wi-Fi air interfacestandards to create a dynamic mesh network between two or more smallcells 100. Once the mesh network has been established, the small cells100 can then communicate in accordance with a signaling protocol orother communication protocol to facilitate intra-cell handovers.

By way of illustrative example, as illustrated in FIG. 8, a first smallcell 100A is in communication with a UE 160 utilizing a first airinterface standard, such as the LTE air interface standard. The firstsmall cell 100A can be configured or otherwise detect the presence ofother small cells, such as small cell 100B. For example, a small cell100 may be able to transmit communications to detect the presence of oneor more small cells within a region. In another example, a small cell100 may be configured with information identifying one or more smallcells that may be within communication range of the specific small cell.Based on a detection of another small cell 100 or an identification ofanother small cell, the two small cells 100A and 100B, can create a meshnetwork. For example, the small cells 100A and 100B can utilize one ofthe two radio frequency bands, such as for example the 5 GHz Wi-Fi band.In some embodiments, the mesh network may be generated by the smallcells in response to communications with one or more UEs 160.Alternatively, the mesh network may be maintained by the small cellsindependent of communications with the UEs.

Utilizing the mesh network, the small cells 100A and 100B illustrativelycoordinate an LTE handover by exchanging information in accordance withsignaling protocols, such as the X2 protocol. In this embodiment,however, the coordination of the handover is accomplished via thewireless mesh network and does not utilize the core network fortransmission or other coordinate functions. As illustrated in FIG. 8,the receiving small cell 100B can process and achieve a handover basedon coordination information exchanged between the two small cells 100.In one aspect, the utilization of a mesh network may have improved speedand performance by facilitating direct communication between the smallcells. In another aspect, the small cells do not require additionalcabling to facilitate the direct connection between the small cells. Instill a further aspect, the composition of the small cells included inthe mesh networks can be dynamically adjusted according to the functionto be implemented, the particular UE or UEs to be handed over, specificservices providers or other criteria. Although the mesh network isillustrated in FIG. 8 as provided in accordance with the Wi-Fi airinterface standard, in other embodiments, the mesh network can also beachieved using other air interface standards instead of, or in additionto a Wi-Fi based mesh network.

In any of the vertical handover scenarios described above, as well as inany handover between a small cell and a backhaul network, it isbeneficial to ensure a uniform quality of service (QoS) acrosstechnologies or networks. In order to achieve a uniform QoS, it isimportant to translate the different QoS standards over the differenttechnologies and networks in order to unify them. FIGS. 9A-9C illustratean embodiment of translation of quality of service standards within aheterogeneous network 200 (FIG. 2).

With reference to FIG. 9A, in an illustrative embodiment, a small cell100 has established communications with a UE 160 in accordance with afirst air interface standard, such as the LTE air interface standard.Illustratively, the UE 160 and small cell 100 can exchange performancemetric information related to the existing communication channel betweenthe UE and the small cell. Examples of the performance metricinformation can include QoS information, other error information,latency information, and the like. Additionally, the performance metricinformation can be embodied in a format specified by the currentlyutilized air interface standard. For example, QoS information can beembodied in the QoS Class Identifier (QCI) standard for communicationsin accordance with the LTE air interface standard. In another example,QoS information can be embodied in the Wi-Fi Multimedia (WMM) standardfor communications in accordance with the Wi-Fi air interface standard.One skilled in the relevant art will appreciate that the aboveidentified examples are illustrative in nature and should not beconstrued as limiting. 6

With continued reference to FIG. 9A, once the performance metricinformation, such QoS information, is received at the small cell 100,the small cell processes the performance metric information. In oneembodiment, the small cell 100 translates the received performancemetric information (e.g., the QoS information) into a format utilizedbetween the small cell 100 and the core network 180. For example, QoSinformation related to communications between the UE 160 and the smallcell 100 that is passed to the core network 180 can be embodied inaccordance with the Differentiated Services Code Point (DSCP) standardor the 802.1p standard. Illustratively, the small cell 100 translatesthe information by mapping the performance metric from onestandard/protocol to a second standard/protocol. Additionally, the smallcell 100 can include additional routing/communication informationutilized to process the translated performance metric information. Forexample, the small cell 100 can include DSCP tag in the generic routingencapsulation (GRE) header used on the GRE tunnel to send traffic on thecore network 180.

With reference now to FIG. 9B, as previously described, the small cell100 may implement an intra-small cell handover in which communicationsbetween the small cell and one or more UEs utilize a second airinterface standard, such as the Wi-Fi air interface standard. Variousembodiments related to the execution of an intra-cell handover have beendescribed above. With reference to FIG. 9C, upon a successfulintra-small cell handover, the UE 160 and small cell 100 can exchangeperformance metric information related to the current communicationchannel between the UE and the small cell (e.g. the Wi-Fi communicationchannel). Illustratively, the performance metric information is embodiedin accordance with the current air interface standard associated withthe communication channel. Additionally, the performance metricinformation may be different from the performance metric informationpreviously exchanged between the UE 160 and the small cell 100 inaccordance with a previously utilized air interface standard.

Similar to the process illustrated in FIG. 9A, in one embodiment, thesmall cell 100 translates the received performance metric information(e.g., the QoS information) into a format utilized between the smallcell 100 and the core network 180. For example, QoS information relatedto communications between the UE 160 and the small cell 100 that ispassed to the core network 180 can be embodied in accordance with thepreviously utilized DSCP standard or the 802.1p standard. The small cell100 can also provide additional routing information as described above.

From the perspective of the components of the core network 180, theperformance metric information exchanged between the small cell 100 andthe core network 180 is independent of the current air interfacestandard utilized between the UE 160 and the small cell 100. Aspreviously described, in some embodiments, the components of the corenetwork 180 may not be provided any knowledge of the current airinterface standard being utilized. Accordingly, the components of thecore network 180 would process received performance metric informationindependent of any knowledge of a current air interface standard.Likewise, the UE 160 would only receive performance metric informationor instructions from the small cell 100 based on the current airinterface standard being utilized between the UE and the small cell. Theperformance metric information or commands received by the UE 160 wouldalso be independent of a format utilized between the small cell 100 andthe components of the core network 180.

Another advantage of the small cell 100 which supports severaltechnologies including LTE and Wi-Fi is that it can improve UE locationresolution. Generally, received signal strength indicator (RSSI)-basedlocation tracking uses trilateration to locate UEs such as mobiledevices. In trilateration, at least three adjacent access points areneeded to resolve any ambiguities. In Wi-Fi networks, neighboring oradjacent access points are assigned different frequency channels tomitigate interference between cells. Therefore, to measure the receivedpower and/or the RSSI of access points near a mobile device, it isnecessary to tune to the channels of neighboring access points. Thistuning might affect QoS for real-time services (including voice andvideo) which are sensitive to time delays because the mobile deviceneeds to switch between channels going from data communications to RTLSand back to data communications.

FIG. 10 illustrates an embodiment for facilitating location basedservices utilizing small cells 100 in a heterogeneous environment 200.As previously described, in one embodiment the small cells 100A, 100Band 100C include multiple air interfaces for communicating with UEs 160.As illustrated in FIG. 10, the UE 160 has a communication channel with asmall cell 100 in accordance with a first air interface, such as the LTEair interface standard. Without implementing a handover, the UE 160 canalso instantiate a second communication channel with the small cell 100Cfor purposes of exchange location information. The second communicationchannel may be maintained continuously or established in a periodic oras needed basis. Illustratively, the UE 160 can obtain locationinformation from the small cell 100C, such as global positioning system(“GPS”) information, geographic coordinates, or other informationutilized to determine an absolute or relative location or positioninformation.

With continued reference to FIG. 10, in accordance with one embodiment,the UE 160 utilizes location information from a three or more smallcells 100 (or other cells) to determine an absolute or relative locationor position. In the illustrated embodiment, the UE 160 can establishcommunications with two other small cells 100A and 100B via the Wi-Fiair interface standard to obtain additional location information. Basedon the location information obtained from multiple small cells 100A,100B, and 100C, the UE 160 can determine absolute or relative locationor position utilizing a variety of known techniques. Additionally,because the UE 160 has utilized an air interface standard not beingutilized for purposes of communications (e.g., the Wi-Fi air interfacestandard), the UE 160 can obtain the location information from the smallcells 100A, 100B and 100C without disrupting the communication channelbetween the UE 160 and the small cell 100C. Additionally, betterlocation resolution is possible since there are a total of six RSSImeasurements (three on each frequency band, for example LTE on the 2.1GHz band and Wi-Fi on the 2.4 GHz band).

Although FIG. 10 illustrates the utilization of the Wi-Fi air interfacestandard for purposes of obtaining location information, the UE 160 andsmall cells 100 can use the LTE interface for determining location ofthe mobile device. Additionally, in this embodiment, the UE 160 canobtain location information from other cells, such as a macro cell 210,that may only support a single air interface standard or that does notnecessarily support a shorter range air interface standard, such as theWi-Fi air interface standard. Still further, in one embodiment, the UE160 may determine location based on location information obtained fromthe small cells 100. Alternatively, the UE 160 may transmit locationinformation, or partially processed location information, to one or morecomponents for determination of location. For example, the UE 160 mayutilize web services that facilitate the determination of location basedon location information provided by the UE.

While illustrative embodiments have been disclosed and discussed, oneskilled in the relevant art will appreciate that additional oralternative embodiments may be implemented within the spirit and scopeof the present disclosure. Additionally, although many embodiments havebeen indicated as illustrative, one skilled in the relevant art willappreciate that the illustrative embodiments do not need to be combinedor implemented together. As such, some illustrative embodiments do notneed to be utilized or implemented in accordance with the scope ofvariations to the present disclosure.

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements or steps. Thus, such conditional language is notgenerally intended to imply that features, elements or steps are in anyway required for one or more embodiments or that one or more embodimentsnecessarily include logic for deciding, with or without user input orprompting, whether these features, elements or steps are included or areto be performed in any particular embodiment. Moreover, unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey utilization of theconjunction “or” in enumerating a list of elements does not limit theselection of only a single element and can include the combination oftwo or more elements.

Any process descriptions, elements, or blocks in the flow diagramsdescribed herein and/or depicted in the attached figures should beunderstood as potentially representing modules, segments, or portions ofcode which include one or more executable instructions for implementingspecific logical functions or steps in the process. Alternateimplementations are included within the scope of the embodimentsdescribed herein in which elements or functions may be deleted, executedout of order from that shown or discussed, including substantiallyconcurrently or in reverse order, depending on the functionalityinvolved, as would be understood by those skilled in the art. It willfurther be appreciated that the data and/or components described abovemay be stored on a computer-readable medium and loaded into memory ofthe computing device using a drive mechanism associated with acomputer-readable medium storing the computer executable components,such as a CD-ROM, DVD-ROM, or network interface. Further, the componentand/or data can be included in a single device or distributed in anymanner. Accordingly, general purpose computing devices may be configuredto implement the processes, algorithms and methodology of the presentdisclosure with the processing and/or execution of the various dataand/or components described above. Alternatively, some or all of themethods described herein may alternatively be embodied in specializedcomputer hardware. In addition, the components referred to herein may beimplemented in hardware, software, firmware or a combination thereof.

It should be emphasized that many variations and modifications may bemade to the above-described embodiments, the elements of which are to beunderstood as being among other acceptable examples. All suchmodifications and variations are intended to be included herein withinthe scope of this disclosure and protected by the following claims.

What is claimed is:
 1. A heterogeneous network comprising: one or moremacro cells, wherein each macro cell is configured to wirelesslycommunicate with a mobile device in accordance with a longer range airinterface standard; and two or more small cells, wherein each small cellis configured to wirelessly communicate with the mobile device inaccordance with the longer range air interface standard and a shorterrange air interface standard; wherein the two or more small cells arefurther configured to implement intra small cell handovers betweencommunications with the mobile device in accordance with the longerrange air interface and the shorter range air interface standards;wherein the two or more small cells are configured to form a meshnetwork based on the shorter range air interface standard; and whereinthe two or more small cells implement inter small cell handoversassociated with communication with the mobile device in accordance withthe longer range air interface standard based on control informationpassed along the mesh network without receiving handover instructionsfrom a core network.
 2. The network as recited in claim 1, wherein thelonger range air interface standard corresponds to the long termevolution air interface standard.
 3. The network as recited in claim 1,wherein the shorter range air interface standard corresponds to IEEE802.11 air interface standard.
 4. The network as recited in claim 1,wherein the two or more small cells are further configured to implementinter small cell handovers between a macro cell and a small cell.
 5. Thenetwork as recited in claim 1, wherein the control informationcorresponds to an X2 protocol.
 6. A network comprising: two or morecells, wherein each of the two or more cells are configured towirelessly communicate with user equipment in accordance with a firstair interface standard and a second air interface standard; and whereinthe two or more cells are configured to form a mesh network utilizingthe second air interface standard; and wherein the two or more cells arefurther configured to implement inter cell handovers betweencommunications with the mobile device in accordance with the first airinterface based on control information passed along the formed meshnetwork.
 7. The network as recited in claim 6, wherein the first airinterface standard corresponds to an air interface standard associatedwith a relatively large geographic range.
 8. The network as recited inclaim 6, wherein the second air interface standard corresponds to an airinterface standard associated with a relatively short geographic range.9. The network as recited in claim 6, wherein the two or more cells areconfigured to implement handovers between a cell implementing only thefirst air interface standard.
 10. The network as recited in claim 6,wherein the two or more cells are configured to utilize a signalingprotocol to control handovers via the communication network.
 11. Thenetwork as recited in claim 6, wherein the formed communication networkcorresponds to a mesh network.
 12. The network as recited in claim 6,wherein the two or more cells are further configured to implement intracell handovers between the first air interface standard and the secondair interface standard.
 13. The apparatus as recited in claim 12,wherein the formed communication network corresponds to a mesh network.14. The apparatus as recited in claim 12, wherein the formedcommunication network is dynamically formed.
 15. The network as recitedin claim 6, wherein the two or more cells are further configured toimplement inter cell handovers without receiving control instructionsfrom a core network.
 16. An apparatus comprising: a first radiocomponent configured to facilitate communication in accordance with afirst air interface standard; a second radio component configured tofacilitate communication in accordance with a second air interfacestandard; wherein the apparatus is configured to form a communicationnetwork with a plurality of cells utilizing the second air interfacestandard; wherein the apparatus is configured to establishcommunications with mobile devices in accordance with the first airinterface standard; and wherein the apparatus is further configured toimplement inter cell handovers between communications with the mobiledevice in accordance with the first air interface standard based oncontrol information passed along the formed communication network. 17.The apparatus as recited in claim 16, wherein the apparatus is furtherconfigured to implement handovers associated with communication with themobile device in accordance solely with the first air interfacestandard.
 18. The apparatus as recited in claim 16, wherein the firstair interface standard corresponds to an air interface standardassociated with a relatively large geographic range.
 19. The apparatusas recited in claim 16, wherein the second air interface standardcorresponds to an air interface standard associated with a relativelyshort geographic range.
 20. The apparatus as recited in claim 16,wherein the apparatus is configured to utilize a signaling protocol tocontrol handovers via the communication network.
 21. A method formanaging communications with user equipment, comprising: in aheterogeneous network including two or more cells, wherein each of thetwo or more cells are configured to wirelessly communicate with userequipment in accordance with a first air interface standard and a secondair interface standard: causing, at a first cell, the formation of acommunication network utilizing the second air interface standard;obtaining, at the first cell, control information associated with ahandover with a second cell via the communication network; and causing ahandover of a mobile device between the first cell and the second cellin accordance with the first air interface standard based, at least inpart, on the control information.
 22. The method as recited in claim 21,wherein the first air interface standard corresponds to an air interfacestandard associated with a relatively large geographic range.
 23. Themethod as recited in claim 21, wherein the second air interface standardcorresponds to an air interface standard associated with a relativelyshort geographic range.
 24. The method as recited in claim 21, whereincausing the formation of the communication network utilizing the secondair interface standard includes utilizing joining an existingcommunication network.
 25. The method as recited in claim 21, whereincausing a handover between the first cell and the second in accordancewith the first air interface standard based, at least in part, on thecontrol information includes utilizing a signaling protocol to controlhandovers via the communication network.
 26. The method as recited inclaim 21, wherein the formed communication network corresponds to a meshnetwork.